Carton for use with packaging apparatus

ABSTRACT

A carton for use with packaging apparatus for packaging food products and the like. The carton is formed of flexible board material and includes rectangular top, bottom, and sidewalls, the end portions of which are provided with fold lines defining top, bottom, and side flaps. The fold line between the bottom wall and one of the sidewalls is provided with spaced-apart cut slots therealong to facilitate the folding of the carton. Each of the bottom flaps is provided with a rectangular notch extending inwardly from the free edge of the flap at about the middle of the length thereof for accommodating a mechanical lifting element on the packaging apparatus. The side flaps are generally rectangular, and the grain of the board material extends generally parallel with the free edge of the bottom flap.

United States Patent Inventors Appl. No.

Filed Patented Assignee Lester E. Cannon Chicago Heights;

John M. Tindall, Wilmette; Howard N. Taylor, Chicago Heights, all of, ill. 868,738

Oct. 23, 1969 May 25, 1971 Folding Cartons, Inc.

Melrose Park, Ill.

Continuation-impart of application Ser. No. 685,140, Nov. 22, 1967, now Patent No. 3,474,594.

CARTON FOR USE WITH PACKAGING APPARATUS 6 Claims, 17 Drawing Figs.

[5 6] References Cited UNITED STATES PATENTS 3,377,767 4/1968 Franz 229/37X Primary Examiner-David M. Bockenek Attorney-Dawson, Tilton, Fallon and Lungmus ABSTRACT: A carton for use with packaging apparatus for packaging food products and the like. The carton is formed of flexible board material and includes rectangular top, bottom, and sidewalls, the end portions of which are provided with fold lines defining top, bottom, and side flaps. The fold line between the bottom wall and one of the sidewalls is provided with spaced-apart cut slots therealong to facilitate the folding of the carton. Each of the bottom flaps is provided with a rectangular notch extending inwardly from the free edge of the flap at about the middle of the length thereof for accommodating a mechanical lifting element on the packaging apparatus. The side flaps are generally rectangular, and the grain of the board material extends generally parallel with the free edge of the bottom flap.

PATENTEDMAYZSIHYI 3580.476

SHEEI 1 BF 5 INVENTORS:

LESTER E. NON JOHN M. Tl LL HOWARD N. TAYLOR ex-flaugfwgllmy mamzawwg ATT'YS PATENTEnuAYzslsn 3580.476

SHEET 3 0F 5 INVENTORS: LESTER E. CANNON JOHN M. TINDALL HOWARD N. TAYLOR BY: mg

AT 'YS PATENIED 25197: Iii-580.476

saw u 0F 5 lNVENTORS: LESTER E. CANNON JOHN M. TINDALL HOWARD N. TAYLOR l3 BY: ATT-Ys PATENTEDmwzsmn 3580.476

SHEEI 5 OF 5 i -mi? INVENTORS:

LES ER E. CANNON JOHN M. TINDALL HOWARD N. TAYLOR BY; ull; awn/a5 CARTON FOR USE WITH PACKAGING APPARATUS Related Application This application is a continuation-in-part of our prior application entitled Packaging Apparatus, Ser. No. 685,140, filed Nov. 22, 1967, now Pat. No. 3,474,594.

BACKGROUND This invention relates to a carton for use with a packaging apparatus for packaging food products such as bacon and the like.

As disclosed in our aforementioned prior patent application, food packaging machines are generally subject to very precise operating requirements which has generally necessitated machine loading, thereby foregoing the advantages of hand loading which enables careful visual inspection of the product, easy loading of irregularly sized products, and the like.

The problem of a satisfactory operation which permits hand loading of the food products into the carton is a combination of providing both the proper packaging apparatus and the proper carton. The carton must be strong to provide protection for the food product yet flexible enough to be manipulated by the packaging apparatus; it must be provided with means for permitting the opening thereof by the packaging apparatus prior to loading; and it must be able to be securely and easily closed after loading.

SUMMARY The inventive carton satisfies the foregoing requirements. The carton is formed'of flexible board material, but the grain of the material runs transverse to the length of the carton to provide strength during the mechanical operations performed thereon. A pair of the fold lines of the carton are provided with spaced cut slots to facilitate setting up" of the carton, and a rectangular notch provided in each of the bottom walls of the carton permits the opening of the carton by the machinery without weakening the carton. The dust flaps or side flaps of the carton are formed by a single knife cut to provide generally rectangular flaps which provide stability to the completed carton.

DESCRIPTION OF THE DRAWINGS The invention will be explained in conjunction with an illustrative embodiment shown in the accompanying drawing, in which:

FIG. 1 is a perspective view taken from one side of the packaging apparatus;

FIG. 2 is a perspective view taken from the other side of the packaging apparatus;

FIG. 3 is a perspective view showing a carton ready to be loaded;

FIG. 4 is a view similar to FIG. 3 but taken from another vantage point;

FIG. 5 is a sectional view illustrating an unloaded carton in solid and a loaded carton in phantom;

FIG. 6 illustrates a flattened carton being moved individually into the loading position;

FIGS. 7, 8, and 9 illustrate the action of the canon cocker on a carton that has been brought to rest in the loading position;

FIG. 10 illustrates a loaded carton being moved'out of the loading position;

FIG. 11 is a top plan view of a carton in a lay-flat condition prior to assembly;

FIG. 12 is a view similar to FIG. 11 showing a carton in state of its assembly; I

FIG. 13 is an end view of the carton in a subsequen'ta'ssembly stage;

FIG. 14 is a fragmentary view taken along the line 14-14 of FIG. 13;

FIGS. 15 and 16 are end views of the carton in subsequent stages of assembly;

one

FIG. 17 is a fragmentary perspective view of one comer of a completed carton.

DESCRIPTION OF SPECIFIC EMBODIMENT It is believed that the invention will be more readily understood if a general description of the carton and a loading apparatus suitable for use with the carton is first given.

Referring to FIGS. 1 and 2, the loading apparatus includes a frame 10 on which is mounted a hopper assembly 11 in which the cartons to be loaded are stacked in a flattened condition. As can be seen in FIGS. 6--9, a carton I2 is delivered individually from the hopper assembly 11 and moved until it reaches a stop assembly 13. A cocking member 33 then forces the flattened carton to assume a generally rectangular cross section. After the carton is stopped and erected, opening assembly 14 (FIG. 4), which includes lifting finger l5 and holddown fingers 16 and 17, forces the loading end 12a of the car ton to assume a wide-open, bowed configuration. Product stop 18 (FIGS. 3 and 5) slides into the other open end 12b of the carton and forces a second lifting finger 19 to rotate upwardly, causing the carton end 12b to assume a bowed configuration, and dust flap closer assemblies 20 and 21 then fold the trailing dust flaps of the carton inwardly. The carton is now ready for loading, following retraction of dust flap closer 21 at the loading side of the carton, and the product may readily be inserted into the widely opened loading end 12a of the carton. Thereafter, the opening assembly 14, product stop 18, dust flap closer assembly 20, and carton cocking members 33, return to their original positions as shown in FIGS. 1 and 2. The stop assembly 13 then permits the carton to be moved out of the loading position, as illustrated in FIG. 10, after which the carton ends 12a and 12b are closed and sealed in the conventional manner.

Referring now to FIGS. ll-l7, the carton 12 is formed from a generally rectangular sheet of flexible paper board material having opposite side edges and 101 and end edges 102 and 103. The sheet is provided with spaced-apart longitudinal score lines or lines of weakness 104, 105, 106, and 107 which extend generally parallel with the side edges 100 and 101 and which divide the paper board sheet into panels 108, 109, I10, 111 and 112. Transverse score lines 113 and 114 extend adjacent the end edges 102 and 103, respectively, generally parallelthereto, and, in cooperation with the longitudinal score lines provide end flaps 115, I16, 117' and 118 along the end edge I02 and end flaps 119, 120, 121, and 122 along the end edge 103. The end flap 116 is severed from the adjacent end flaps and 117 by single knife cuts along the extensions of the longitudinal score lines 104 and 105 beyond the transverse score line 113. Similarly, the other relatively narrow end flaps 118, 120 and 122 are severed from their adjacent wider end flaps by single knife cuts along the extensions of the longitudinal score lines beyond the transverse score lines to provide generally rectangular individual flaps which will serve as dust flaps in the completed carton. The outer ends of each of the side edges of the flap 116 are provided with a 45 cut as at 1160 to facilitate tucking of the flap Into the assembled carton, and the: other narrow flaps are similarly provided with the 45 cuts.

Longitudinal score lines 105 and 107 are provided with spaced-apart slots 105a and 107a, respectively, cut therethrough to increase the ability of the paper board sheet to bend or. fold along the score lines. Preferably, the slots 105a and 1070 are about five-eighths inch long and are spaced about three-eighths inch apart. The slots adjacent the transverse scorelines 113 and 114 may be spaced about eleven-sixteenths inch therefrom.

The end flap 102 is provided with a notch 123 which extends inwardly from the free edge 102 of the flap, and the opposite end flap 120 is similarly provided with a notch-124 extending inwardly from the edge 103 thereof. Each of the notches I24 and 123 are preferably generally rectangular and extend inwardly for approximately one-half of the depth-0f the flap.

If desired, the panel 108, which will become the top panel or wall of the completed carton may be cut out to provide a window 125 which may be covered with a transparent sheet 126 to permit visual inspection of the contents of the package. Also, the flap 112, which will serve as an opening flap for the carton, may be provided with angled end edges 112a and 11% which extend inwardly from score lines 113 and 1141.

Prior to assembly of the carton, an adhesive layer or strip 127 is applied to the flaps 116 and 117, and an adhesive strip 128 is applied to the opposite flaps 120 and 121. Each of the adhesive strips 127 and 128 extend from adjacent the respective transverse score lines 113 and 114 outwardly for about half the width of the end flaps. Another adhesive strip 129 is applied to the panel 10%} adjacent the side edge 100 thereof. The adhesive strips may be applied in the conventional manner, as by rollers or the like, and any suitable adhesive may be used, although hot melt sealants are preferred.

The carton 12 is preferably formed of paper board sheet having a board weight of about l or 16 points, i.e., a thickness of about 0.015 or 0.016 inch, and the paper board is positioned so that the grain thereof runs transversely of the carton, i.e., perpendicular to the score lines 104-107.

The carton is assembled for stacking in the hopper assembly 11 of the loading apparatus by folding the paper board sheet along the score lines 104 and 106 and securing the panel 112 to the panel 108 by means of the adhesive strip 129 to form the flattened or collapsed carton 12 illustrated in FIG. 12. The flattened cartons 12 are stacked in the hopper assembly 11 as illustrated in FIGS. 6-10 and are pulled therefrom by picker knife 26 which engages the trailing edge 12 provided by the score line 106. The construction and operation of the hopper assembly and picker knife 26, as well as other portions of the apparatus, is described in detail in our copending prior application Ser. No. 685,140, filed Nov. 22, 1967, to which reference may be had for a more detailed description.

A doctor blade 29 is attached to hopper rail 24 and is spaced from the carton-supporting frame 25 to provide clearance for only a single carton 12. A pair of hold-back dogs 30 are slidably mounted on the doctor knife 29 and are provided with inclined bottom edges so that forward movement of the carton 12'forces the dogs upwardly, permitting the carton 12 to pass beneath the doctor blade 29.

The carton 12 is pushed along the carton-supporting frame, which defines the path of carton advance, by picker knife 26 until the leading edge 12d provided by the score line 104! approaches the stop assembly 13. At that time the piston as sociated with the picker knife reaches the end of its stroke, and the picker knife 26 returns to the hopper assembly in position to engage another carton. After forward movement of the picker knife 26 stops, the hold-back dogs 30 drop down to prevent the carton from moving rearwardly with the picker knife. The momentum of the carton 12 carries the carton into stop dogs 31 (FIG. 7) which stop the carton. Each stop dog 31 is pivotally mounted as at 32 to one of the beams 25b and 25c so that a major portion of the stop dog extends downwardly from the pivot point to act as a counterweight. The force imposed on the stop dogs 31 by the forwardly moving carton 12 is not sufficient to rotate the counterweights upwardly and the carton is therefore brought to rest.

Thereafter, carton cockers 33, which are also rotatably mounted on beams 25b and 25c, are rotated upwardly in the direction of the arrow in FIG. 7 to engage the leading edge 12d of the carton. Each carton cocker is attached to a pinion gear 34 which engages a rack 35 slidably mounted on one of the beams 25b and 250. A pneumatic cylinder and piston 36 (FIG. 8) is also mounted on the frame to move rack 35 forwardly and rotate the carton cocker to engage the carton. As the carton cocker rotates, the trailing edge 12c of the carton is pushed back against the hold-back dogs 30, which had dropped downwardly after the carton passed. Further rotation of the carton cocker causes the flattened carton to set up" or assume a generally rectangular longitudinal cross section as in FIG. 9. The carton sets up by bending about the cut-score lines and 107, and the spaced-apart cuts provided along these score lines facilitates the bending and setting up of the carton. However, the transversely running grain of the carton provides strength as the carton is engaged by the carton cocker and prevents the carton from being crushed or damaged during this operation.

As soon as the carton is set up, the carton opening assembly 14, product stop 10, and members 16, 17, 20 and 21 are activated to prepare the carton for loading. Referring to FIGS. 3- 5, lifting finger 15 is attached to rod 37 which isjournaled in posts 38 and 39 secured to frame 10. Air cylinder 40 is also mounted on the frame and activates a piston 46 which is connected to rod 441 by connector 47 and crank arm 48. Lifting finger 15 and holddown fingers 16 and 17 are shown in the nonloading positions in FIGS. 1, 2, and in solid in FIG. 5, and the holddown fingers are seen to extend upwardly through notches a9 and 50 (FIG. 4) provided in loading platform-51 secured to the frame. The product that is to be loaded is fed onto the platform 51 by means of a conveyor or the like and the upwardly extending holddown fingers l6 and 17 and the downwardly extending lifting finger 15 prevent the product from moving toward the carton until the carton is ready'for loading.

After the carton cookers 33 set up the carton, the air cylinder 40 is activated to rotate the lifting finger 15 into engagement with the panel 108 which forms the top wall of the carton while the air cylinder 45 is activated to rotate the holddown fingers 16 and 17 into engagement with the panel which forms the carton bottom wall. As can be seen in FIG. 5, the rectangular notch 124 provided midway along the end flap 121 permits the lifting finger to engage the carton top 108 even if the carton is not properly set up by the carton cocker. The lifting finger 15 rotates upwardly through the rectangular notch to engage the carton top and raise it to the position shown in phantom and indicated at 108. The carton cocker and back stop 30 insure that the notch is closely positioned with respect to the finger 15, and the rectangular configuration of the notch, with a dimension extending in the direction of carton travel, insures that the finger 15 may pass upwardly through the notch even if a slight variation in position of the carton along the subframe 25 exists. However, the rectangular nature of the notch minimizes any structural weakness provided in the end flaps.

The loading end 12 of the carton is shown in the fully opened position in FIG. 4, and the carton top 108 is seen to be bowed upwardly against arcuately shaped restraining rail 52, which prevents excessive upward movement of the lifting finger. I

At the same time as the opening assembly 14 is activated, product stop 18 is pushed transversely by air cylinder and piston 53 into the opened end 12 of the carton. A second lifting finger 19 is rotatably mounted by arm 56 above product stop 18, and as the product stop is urged toward its loading position indicated in phantom at 18 in FIG. 5, the lifting finger 19 is forced to rotate upwardly by the upper surface of the product stop. As the lifting finger 19 rotates, it engages the carton top 100 and lifts it toward the restraining rail 57 at 108". The rectangular notch 123 provided in the end flap 1 1'7 permits the lifting finger 19 to engage the carton top even if the carton is not properly set up by the carton cocker.

At the same time the loading end 12a of the carton is being opened and the product stop is being positioned within the carton, the dust flap closing assemblies 20 and 21 are activated to fold the trailing end flaps or dust flaps 118 and 122 into the carton. Referring to FIG. 2, dust flap closing assembly 20 includes an air cylinder and piston assembly 50 mounted on the frame and a rack and pinion gear 59 and 60, respectively. Similarly, closing assembly 21 includes air cylinder and piston assembly 61 mounted on doctor blade 29 and rack and pinion gear 62 and 63, respectively. Referring to FIG. 41, pinion gear 63 is attached to one end of shaft 6 1 which is rotatably received within a bushing 65 attached to front rail 20 of the hopper assembly 11. Finger 66 is attached to the other end of shaft 64 and is rotatable to force the dust flap 122 into the carton by linear movement of the rack 62. Dust flap closing assembly 20 is similarly constructed to force dust flap 118 into the carton. While closing assembly 20 remains in its extended position within the carton until after the carton is loaded, retracting along with the product stop, the dust flap closing assembly 21 returns immediately to its original retracted position prior to loading of the carton.

The carton is now in the loading condition, and the product may be slid along platform 51 into the loading end 12a of the carton and pushed against product stop 18. When the holddown fingers are in their loading positions, e.g., 17 in FIG. 5, they protrude only slightly above platform 51, and the product easily slides over the top of the curved fingers. The product may be loaded either manually or automatically, and because the carton is loaded while stationary, no complicated loading machinery is required. Further, manual loading of the product permits visual inspection of the product before it is loaded and enables irregularly sized products to be loaded without difficulty.

No special placement of the product within the carton is necessary. The product, indicated in phantom at 67 in FIG. 5, is merely pushed into the carton until it contacts the product stop. There is therefore no danger that the product may be inserted too far into the carton and push the dust flap 118 out of the carton.

As can be seen in FIG. 5, the canon top 108 is lifted higher at the loading end, as at 108, than at the opposite end, as at 108". The widely opened loading end facilitates loading, while the other end need be opened only so far as to ensure that the upper surface of the product is not smudged or disarranged as the product is positioned.

After the carton has been loaded, the operator depresses hand-actuated lever 68 (FIG. 1), which is operatively associated with air cylinders 36, 40, 45, and 53 and is programmed to cycle the entire machine. When the actuator 68 is depressed, air pressure is withdrawn from these cylinders to allow the spring-urged pistons to return to their unactivated positions, thereby returning carton cockers 37, lifting finger 15, holddown fingers 16 and 17 and product stop 18, respectively, to their original, nonloading positions. Thereafter, the picker knife 26 is again moved forwardly to withdraw a second carton from the hopper assembly. Pusher dogs 75 which reciprocate with the picker knife and shift the series of loaded cartons forwardly, such dogs being automatically cammed by engagement with the carton into retracted positions as the dogs and picker knife later shift rearwardly. As illustrated in FIG. 10, the picker knife urges the second carton 12' against the first carton 12, although, if desired, a stop dog identical to dogs 75 may be interposed between the carton cocker 33 and the stop 30 to advance carton 12 without contact by carton 12'. The pickerknife 26 provides a sufficient force to swing the counterweight portion of stop dog 31 upwardly, thereby permitting the carton 12 to proceed forwardly beyond the stop assembly. As the carton 12 proceeds forwardly, plows 69 and 70 (FIG. 3) fold the leading dust flaps 117 and 120 into the canon. As the'carton is moved forwardly by pusher dogs 75, the end flaps 115, 117, 119 and 121 are closed in the conventional manner and suitably sealed as by heat sealing.

FIG. 13 is an end view of a carton 12 after the carton has been loaded and the trailing dust flaps 118 and 122 and the lead. dust flaps 116 and 120 have been folded inwardly. Thereafter, as the carton moves along the frame of the loading apparatus, the end flaps 117 and 121 are plowed upwardly as illustrated in FIG. 15, and the end flaps 115 and 119 are plowed downwardly as illustrated in FIG. 16. The score lines 113 and 114 facilitate the bending of these flaps to close the carton ends. Thereafter, the ends of the carton are heated to melt the adhesive strips and to seal the dust flaps 116 and 120 to the end flaps 117 and 121, respectively, and to seal the end flaps 117 and 121 to the end flaps I and 119 respectively.

The product can be readily removed from the carton by means of the panel 112. The panel 112 is wider than the adhesive strip 129, and the free edge 101 of the panel is therefore not secured to the top panel 108 and forms an opener flap. The fingers of one hand can be inserted between the panels 112 and 108, and the panel 112 can be pulled upwardly to destroy the adhesive bond to the top panel 108. The panel 112 and the panel 111, which forms one of the sidewalls of the carton, may then be bent outwardly about the score line 106 to permit the product to be removed from between the top and bottom panels 108 and 110 from the left-hand side as viewed in FIG. 13. The dust flaps 118 and 122 are not adhesively secured to the other end flaps and may be readily withdrawn from between the top and bottom panels as the sidewall panel 111 flexes about the score line 106.

It is frequently desired to replace the product in the carton after a portion thereof is removed. For example, if the product is sliced bacon, the bacon may be replaced in the carton after several slices have been removed. Thereafter, the carton can be closed by folding the sidewall panel 111 and panel 112 about the score line 106 and tucking the panel 112 into the carton below the top panel 108. Referring again to FIG. 13, the generally rectangular flaps 118 and 122 are provided with straight edges by virtue of the single knife cut, and these straight edges bear against the top bottom panels to inhibit bending of the sidewall panel 111 about the score line 106 and to maintain the carton in the; closed condition. Further, the generally rectangular dust flaps provide the carton with greater stability and resistance against crushing.

In one specific embodiment of a carton designed for use in packaging I pound of sliced bacon, the longitudinal dimension of the assembled carton, i.e., the distance between the transverse score lines 113 and 114 was 10 inches, and each of the top and bottom panels 108 and 110 was 5-15/16 inches wide. The distance between the longitudinal score lines 104 and and the score lines 106 and 107 which provide the sidewalls of the carton was five-eighths inch. The distance between the transverse score line 113 and carton edge 102 and the distance between the transverse score line 114 and carton edge 103 was also five-eighths inch. The notches 123 and 124 were each one-half inch wide and extended inwardly from the edges 102 and 103 five-sixteenth of an inch. The center of each notch was 2-3/32 inches from the score lines 105 and 106. The panel 112 provided by the score line 107 was 1-3/16 inches wide. The notched portions of the dust flaps, for example 1611 on flap 16, were out along a 45 angle to the edges 102 and 103, and the length of the notches along the edges was one-eighth inch.

While in the foregoing specification, a detailed description of a specific embodimentof our invention was set forthfor the purpose of illustration, it is to be understood that many of the details herein given may be varied considerably by those skilled in the art without departing from the spirit and scope of the invention.

We claim:

1. A carton formed of flexible board material and having rectangular top, bottom and sidewalls and being open at opposite ends, the end portions of said top, bottom, and sidewalls being provided with fold lines defining top, bottom, and side flaps, each of said top and bottom flaps being generally rectangular and having an outer free edge, each of the top and bottom flaps being separated from the adjacent side flaps by a single knife cut to provide the side flaps with a generally rectangular shape, each of the side flaps including an outer free edge extending generally parallel to the free edges of the top and bottom flaps when the carton is in a lay-flat condition anda pair of parallel side edges extending generally perpendicular to the outer free. edge of the side flap, each of said bottom flaps being provided with a rectangular notch extending inwardly from the free edge of such flap approximately midway along the length of the bottom flap, the free edge of each of the top flaps extendingoutwardly beyond the innermost portion of the notch of the bottom flap below the top flap whereby a mechanical lifting element can pass upwardly through each notch to engage and lift the top flap thereabove,

the bottom wall and one of the sidewalls being joined by a fold line provided by a score line having spaced-apart slots cut therethrough, the carton including an opener flap extending from one of the sidewalls above the top wall and adhesively secured to the top wall, said opener flap being joined to said one sidewall by a fold line provided by a score line having spaced-apart slots cut therethrough.

2. The carton of claim 1 in which said spaced-apart slots are about five-eighths of an inch long and are spaced about three eighths of an inch apart.

3. The carton of claim 1 in which the outer ends of the side flaps are provided with about a 45 cut between the outer free edge and each side edge.

4. The carton of claim 1 in which the grain of the board material extends generally parallel with the free edges of the bottom flaps.

5. A generally rectangular sheet of flexible paper board material for forming a carton, said sheet having:

a. four spaced-apart parallel fold lines defining the longitudinal dimensions of the carton to be formed, the second and fourth fold lines being provided with spaced-apart slots cut therethrough;

b. a first edge spaced from the first fold line and extending generally parallel therewith;

c. a second edge spaced from the fourth fold line;

d. third and fourth edges extending generally transversely to the first edge;

e. a transverse fold line spaced inwardly from each of said third and fourth edges and extending parallel therewith; the portions of the longitudinal fold lines extending outwardly of the transverse fold lines being single-knife cut provide flaps between adjacent longitudinal fold lines having edges which extend generally perpendicular to the transverse fold lines; and

f. a rectangular notch extending inwardly from each of the third and fourth edges about midway between the second and third fold lines.

6. The sheet of claim 5 in which the spaced-apart slots are about five-eighths of an inch long and are spaced about threeeighths of an inch apart. 

1. A carton formed of flexible board material and having rectangular top, bottom and sidewalls and being open at opposite ends, the end portions of said top, bottom, and sidewalls being provided with fold lines defining top, bottom, and side flaps, each of said top and bottom flaps being generally rectangular and having an outer free edge, each of the top and bottom flaps being separated from the adjacent side flaps by a single knife cut to provide the side flaps with a generally rectangular shape, each of the side flaps including an outer free edge extending generally parallel to the free edges of the top and bottom flaps when the carton is in a lay-flat condition and a pair of parallel side edges extending generally perpendicular to the outer free edge of the side flap, each of said bottom flaps being provided with a rectangular notch extending inwardly from the free edge of such flap approximately midway along the length of the bottom flap, the free edge of each of the top flaps extending outwardly beyond the innermost portion of the notch of the bottom flap below the top flap whereby a mechanical lifting element can pass upwardly through each notch to engage and lift the top flap thereabove, the bottom wall and one of the sidewalls being joined by a fold line provided by a score line having spaced-apart slots cut therethrough, the carton including an opener flap extending from one of the sidewalls above the top wall and adhesively secured to the top wall, said opener flap being joined to said one sidewall by a fold line provided by a score line having spaced-apart slots cut therethrough.
 2. The carton of claim 1 in which said spaced-apart slots are about five-eighths of an inch long and are spaced about three-eighths of an inch apart.
 3. The carton of claim 1 in which the outer ends of the side flaps are provided with about a 45* cut between the outer free edge and each side edge.
 4. The carton of claim 1 in which the grain of the board material extends generally parallel with the free edges of the bottom flaps.
 5. A generally rectangular sheet of flexible paper board material for forming a carton, said sheet having: a. four spaced-apart parallel fold lines defining the longitudinal dimensions of the carton to be formed, the second and fourth fold lines being provided with spaced-apart slots cut therethrough; b. a first edge spaced from the first fold line and extending generally parallel therewith; c. a second edge spaced from the fourth fold line; d. third and fourth edges extending generally transversely to the first edge; e. a transverse fold line spaced inwardly from each of said third and fourth edges and extending parallel therewith; the portions of the longitudinal fold lines extending outwardly of the transverse fold lines being single-knife cut provide flaps between adjacent longitudinal fold lines having edges which extend generally perpendicular to the transverse fold lines; and f. a rectangular notch extending inwardly from each of the third and fourth edges about midway between the second and third fold lines.
 6. The sheet of claim 5 in which the spaced-apart slots are about five-eighths of an inch long and are spaced about three-eighths of an inch apart. 